PC-based computing system having an integrated graphics subsystem supporting parallel graphics processing operations across a plurality of different graphics processing units (GPUS) from the same or different vendors, in a manner transparent to graphics applications

ABSTRACT

PC-based computing system having an integrated graphics subsystem supporting parallel graphics processing operations across a plurality of different graphics processing units (GPUs) supplied from the same or different vendors. The graphics subsystem include a graphics controller hub (GCH) chip located on a CPU bus, and having Multi-Pipeline Core Logic (MP-CL) circuitry including a routing unit and a control unit. The plurality of different GPUs are interfaced with the GCH chip. Each different GPU supports a GPU-driven pipeline core having a frame buffer (FB) for storing a fragment of pixel data. The GPU-driven pipeline cores are arranged in a parallel architecture and operated according to a parallelization mode of operation, so that said GPU-driven pipeline cores process data in a parallel manner. In one illustrative embodiment, the different GPUs are located (i) within an integrated graphics device (IGD) within the GCH chip, and also (ii) on one or more external GPU-based graphics cards from the same or different vendors. In another illustrative embodiment, the different GPUs are located on a plurality of external GPU-based graphics cards from different vendors. Diverse illustrative embodiments are disclosed.

RELATED CASES

This Application is a Continuation of copending U.S. application Ser.No. 11/386,454 filed Mar. 22, 2006; which is a Continuation-in-Part(CIP) of copending U.S. application Ser. No. 11/340,402 filed on Jan.25, 2006, which is a CIP of: provisional Application No. 60/647,146filed Jan. 25, 2005; International Application No. PCT/IL2004/000079filed Jan. 28, 2004; and International Application No. PCT/IL2004/001069filed Nov. 19, 2004, entered in the U.S. National Stage as U.S.application Ser. No. 10/579,682, and based on U.S. provisionalApplication Nos. 60/523,084 and 60/523,102, both filed Nov. 19, 2003;each said Application being commonly owned by Lucid InformationTechnology Ltd, of Israel, and incorporated herein by reference as ifset forth fully herein.

BACKGROUND OF INVENTION Field of the Invention

Over the past few decades, much of the research and development in thegraphics architecture field has been concerned the ways to improve theperformance of three-dimensional (3D) computer graphics rendering.Graphics architecture is driven by the same advances in semiconductortechnology that have driven general-purpose computer architecture. Manyof the same acceleration techniques have been used in this field,including pipelining and parallelism. The graphics renderingapplication, however, imposes special demands and makes available newopportunities. For example, since image display generally involves alarge number of repetitive calculations, it can more easily exploitmassive parallelism than can general-purpose computations.

In high-performance graphics systems, the number of computations highlyexceeds the capabilities of a single processing unit, so parallelsystems have become the rule of graphics architectures. A veryhigh-level of parallelism is applied today in silicon-based graphicsprocessing units (GPU), to perform graphics computations. Typicallythese computations are performed by graphics pipeline, supported byvideo memory, which are part of a graphic system.

FIG. 1A1 shows a conventional graphic system as part of a PCarchitecture, comprising: a CPU (111), system memory (112), chipset(113, 117), high speed CPU-GPU bus (114) (e.g. PCI express 16×), video(graphic) card (115) based on a single GPU, and display (116). FIG. 1A2shows prior art chipset 113 and 117 being realized using Intel'schipsets comprising the 82915G chip (i.e. a Graphics and MemoryController Hub with an integrated graphics device IGD, also called the“NorthBridge” chip) and the ICH6 chip, called the I/O hub. In FIG. 1A3,another prior art chipset 113, 117 is realized using Intel's chipsetcomprising the 82915PL chip (i.e. the Memory Controller Hub (MCH)without an integrated graphics device IGD, also called the NorthBridgechip) and the ICH6x chip (i.e. the I/O hub). Examples of otherNorthBridge chips include: AMD-761 by Advanced Micro Devices (AMD);K8T900 by VIA; CrossFire Xpress 3200 chipset by ATI; nForce4 by Nvidia;and SIS662 by SIS.

In addition to driving the system memory (123), the GMCH 113′ includesan integrated graphics device (IGD) that is capable of driving up tothree displays (116′″). Notably, the GMCH 113′ does not support adedicated local graphics memory; instead it uses part of the systemmemory 112. Also GMCH 113′ has the capability of supporting externalgraphics accelerators (115) via the PCI Express Graphics port but cannotwork concurrently with the integrated graphics device (IGD). As shown inFIG. 1A3, the Memory Controller Hub (MCH) (i.e. 82915PL) 113″ supportsexternal graphics (115, 116) only, and provides no integrated graphicsdevice (IGD) support, as GMCH 113′ in FIG. 1A2. Also, prior art Intel®chipsets 113′ and 113″ lack generic capabilities for driving the GPUs ofother major vendors, and are unable to support Nvidia's SLI graphicscards.

As shown in FIG. 2A1, the single GPU graphic pipeline can be decomposedinto two major components: a geometry subsystem for processing 3Dgraphics primitives (e.g. polygons); and a pixel subsystem for computingpixel values. These two components are consistently designed forincreased parallelism. As shown in FIG. 2A2, the graphics pipeline of aprior art integrated graphics device (IGD) is shown comprising: a memorycontroller for feeding a video engine, a 2D engine and a 3D engine,which feeds a display engine, which in turn, feeds a Port Mux Controlleralong the way to an analog or digital display.

In the geometry subsystem, the graphics databases are regular, typicallyconsisting of a large number of primitives that receive nearly identicalprocessing; therefore the natural concurrency is to partition the datainto separate streams and to process them independently. In the pixelsubsystem, image parallelism has long been an attractive approach forhigh-speed rasterization architectures, since pixels can be generated inparallel in many ways. An example of a highly parallel GraphicProcessing Unit chip (GPU) in prior art is depicted in FIG. 2B1 (takenfrom 3D Architecture White Paper, by ATI). The geometry subsystemconsists of six (6) parallel pipes while the pixel subsystem has sixteen(16) parallel pipes.

However, as shown in FIG. 2B2, the “converge stage” 221 between thesetwo subsystems is very problematic as it must handle the full datastream bandwidth. In the pixel subsystem, the multiple streams oftransformed and clipped primitives must be directed to the processorsdoing rasterization. This can require sorting primitives based onspatial information while different processors are assigned to differentscreen regions. A second difficulty in the parallel pixel stage is thatordering of data may change as those data pass through parallelprocessors. For example, one processor may transform two smallprimitives before another processor transforms a single, large one.Certain global commands, such as commands to update one window insteadof another, or to switch between double buffers, require that data besynchronized before and after command. This converge stage between thegeometry and pixel stages, restricts the parallelism in a single GPU.

A typical technology increasing the level of parallelism employsmultiple GPU-cards, or multiple GPU chips on a card, where the renderingperformance is additionally improved, beyond the converge limitation ina single core GPU. This technique is practiced today by several academicresearches (e.g. Chromium parallel graphics system by StanfordUniversity) and commercial products (e.g. SLI—a dual GPU system byNvidia, Crossfire—a dual GPU by ATI). FIG. 3 shows a commercial dual GPUsystem, Asus A8N-SLI, based on Nvidia SLI technology.

Parallelization is capable of increasing performance by releasingbottlenecks in graphic systems. FIG. 2C indicates typical bottlenecks ina graphic pipeline that breaks-down into segmented stages of bustransfer, geometric processing and fragment fill bound processing. Agiven pipeline is only as strong as the weakest link of one of the abovestages, thus the main bottleneck determines overall throughput. Asindicated in FIG. 2C, pipeline bottlenecks stem from: (231) geometry,texture, animation and meta data transfer; (232) geometry data memorylimits; (233) texture data memory limits; (234) geometrytransformations; and (235) fragment rendering.

There are different ways to parallelize the GPUs, such as: time-division(each GPU renders the next successive frame); image-division (each GPUrenders a subset of the pixels of each frame); and object-division (eachGPU renders a subset of the whole data, including geometry andtextures), and derivatives and combinations of thereof. Althoughpromising, this approach of parallelizing cluster of GPU chips suffersfrom some inherent problems, such as: restricted bandwidth of inter-GPUcommunication; mechanical complexity (e.g. size, power, and heat);redundancy of components; and high cost.

Thus, there is a great need in the art for an improved method of andapparatus for high-speed graphics processing and display, which avoidsthe shortcomings and drawbacks of such prior art apparatus andmethodologies.

OBJECTS AND SUMMARY OF THE PRESENT INVENTION

Accordingly, a primary object of the present invention is to provide anovel method of and apparatus for high-speed graphics processing anddisplay, which avoid the shortcomings and drawbacks of prior artapparatus and methodologies.

Another object of the present invention is to provide a novel graphicsprocessing and display system having multiple graphics cores withunlimited graphics parallelism, getting around the inherent convergebottleneck of a single GPU system.

Another object of the present invention is to provide a novel graphicsprocessing and display system which ensures the best graphicsperformance, eliminating the shortages of a multi-chip system, therestricted bandwidth of inter-GPU communication, mechanical complexity(size, power, and heat), redundancy of components, and high cost.

Another object of the present invention is to provide a novel graphicsprocessing and display system that has an amplified graphics processingand display power by parallelizing multiple graphic cores in a singlesilicon chip.

Another object of the present invention is to provide a novel graphicsprocessing and display system that is realized on a silicon chip havinga non-restricted number of multiple graphic cores.

Another object of the present invention is to provide a novel graphicsprocessing and display system that is realized on a silicon chip whichutilizes a cluster of multiple graphic cores.

Another object of the present invention is to provide a novel graphicsprocessing and display system that is realized on a silicon chip havingmultiple graphic cores or pipes (i.e. a multiple-pipe system-on-chip, orMP-SOC) and providing architectural flexibility to achieve the advancedparallel graphics display performance.

Another object of the present invention is to provide a novel graphicsprocessing and display system that is realized on a silicon chip havingmultiple graphic cores, and adaptively supporting different modes ofparallelism within both its geometry and pixel processing subsystems.

Another object of the present invention is to provide a novel graphicsprocessing and display system that is realized on a silicon chip havingmultiple GPU cores, and providing adaptivity for highly advancedgraphics processing and display performance.

Another object of the present invention is to provide a novel graphicsprocessing and display system and method, wherein the graphic pipelinebottlenecks of vertex (i.e. 3D polygon geometry) processing and fragmentprocessing are transparently and intelligently resolved.

Another object of the present invention is to provide a method andsystem for an intelligent decomposition of data and graphic commands,preserving the basic features of graphic libraries as state machines andtightly sticking to the graphic standard.

Another object of the present invention is to provide a new PCI graphicscard supporting a graphics processing and display system realized on asilicon chip having multiple graphic cores, and providing architecturalflexibility to achieve the best parallel performance.

Another object of the present invention is to provide a computing systemhaving improved graphics processing and display capabilities, employinga graphics card having a silicon chip with multiple graphic cores, andproviding architectural flexibility to achieve the best parallelperformance.

Another object of the present invention is to provide a novel graphicsprocessing and display system comprising multi-pipeline (MP) Core Logiccircuitry including a routing center, a compositing unit, a control unitand a profiling functions module.

Another object of the present invention is to provide a Graphics andMemory Controller Hub (GMCH) chip comprising a graphics subsystemincluding dual Integrated Graphics Devices (IGDs) driven by the MP-CLcircuitry of the present invention specified in FIG. 4F.

Another object of the present invention is to provide an improvedNorthBridge chip that can be used to replace prior art NorthBridge chipsemployed in PC architectures, wherein the Northbridge chip of thepresent invention comprises a graphics subsystem including a dual3D-pipeline driven by the MP-CL circuitry of the present invention.

Another object of the present invention is to provide a Graphics andMemory Controller Hub (GMCH) chip that can be used to replace prior artGMCH chips employed in PC architectures, wherein the GMCH chip of thepresent invention comprises a graphics subsystem including a dual3D-pipeline driven by the MP-CL circuitry.

Another object of the present invention is to provide a Graphics andMemory Controller Hub (GMCH) that can be used to replace prior art GMCHchips employed in PC architectures, wherein the GMCH chip of the presentinvention comprises graphics subsystem including a single IGD and MP-CLcircuitry integrated therein to drive external GPU cards.

Another object of the present invention is to provide a MemoryController Hub (MCH) chip that can be used to replace prior art MCHchips employed in PC architectures, wherein the MCH chip of the presentinvention comprises MP-CL circuitry for driving external GPU cards, or asingle card with multiple GPUs, or a single GPU card, and wherein onlythe routing center is used for passing data to and from the externalGPUs.

Another object of the present invention is to provide a high performancecomputer graphics system employing a GMCH chip, wherein the graphicssubsystem includes a dual IDG processor having the MP-CL circuitry ofthe present invention integrated therein, for driving a single displaydevice.

Another object of the present invention is to provide a high performancecomputer graphics system employing a GMCH chip or a MCH chip, whereinthe graphics subsystem includes the MP-CL circuitry of the presentcircuitry of the present invention integrated therein, for drivingmultiple single-GPU based graphics cards interfaced to multiple displaydevices.

Another object of the present invention is to provide a high performancecomputer graphics system employing either a GMCH chip or a MCH chip,wherein the graphics subsystem includes the MP-CL circuitry of thepresent invention integrated therein, for driving a multi-GPU basedgraphics card interfaced to a display device.

Another object of the present invention is to provide a high performancecomputer graphics system employing either a GMCH chip or a MCH chip,wherein MP-SOC Core Logic circuitry of the present invention isintegrated therein, for driving a single-GPU based graphics cardinterfaced to a display device.

Another object of the present invention to provide such a computingsystem having improved graphics processing and display performancerequired by applications including, video-gaming, virtual reality,scientific visualization, and other interactive application requiring ordemanding photo-realistic graphics display capabilities.

These and other objects and advantages of the present invention willbecome apparent hereinafter.

BRIEF DESCRIPTION OF DRAWINGS OF THE PRESENT INVENTION

For a more complete understanding of how to practice the Objects of thePresent Invention, the following Detailed Description of theIllustrative Embodiments can be read in conjunction with theaccompanying Drawings, briefly described below, wherein:

FIG. 1A1 is a schematic representation of a prior art, standard PCarchitecture, in which its conventional single GPU graphic card is showncircled;

FIG. 1A2 is a schematic representation of a prior art, standard PCarchitecture employing Intel's Express chipset for the 82915G Graphicsand Memory Controller Hub (GMCH);

FIG. 1A3 is a schematic representation of a prior art, standard PCarchitecture employing Intel's Express chipset for the 82915PL MemoryController Hub (MCH), driving external graphics only;

FIG. 2A1 is a simplified block diagram of a prior art conventionalgraphics system employing a single GPU, having geometry and pixelprocessing subsystems, wherein the data converge stream between thesubsystems presents a serious system bottleneck that significantlylimits performance;

FIG. 2A2 is a schematic block diagram for the Integrated Graphics Devicewithin the Intel 82915G Graphics and Memory Controller Hub (GMCH);

FIG. 2B1 is a simplified block diagram illustrating high parallelism ina typical prior art ATI X800 Graphic Processing Unit chip (GPU), whereinthe geometry subsystem consists of 6 parallel pipes and the pixelsubsystem consists of 16 parallel pipes;

FIG. 2B2 is a schematic diagram of the internal portion of a prior artgraphic processing unit (GPU) chip (e.g. ATI X800) illustrating thebottlenecking converge stage (setup engine) between geometric and pixelparallel engines therein;

FIG. 2C is a schematic representation of a conventional graphicspipeline, illustrating the data bottleneck problem existing therein;

FIG. 3 is a photograph of a prior art dual GPU-driven video graphicscard;

FIG. 4A is a schematic system block diagram representation of a graphicsystem based on a printed circuit graphics card employing themultiple-pipe system-on-chip (MP-SOC) device in accordance with theprinciples of the present invention, wherein the system block diagramshows the CPU, the memory bridge of the I/O chipset, system memory, aprinted-circuit (PC) video graphics board based on the MP-SOC of thepresent invention, and display screen(s);

FIG. 4B is schematic representation of the physical implementation ofthe MP-SOC of the present invention, mounted on a printed circuit (PC)video graphics board;

FIG. 4C is a photograph of a standard PCI express graphics slot on amotherboard to which the MP-SOC-based PC graphics board of the presentinvention is interconnected;

FIG. 4D is a schematic representation of an exemplary MP-SOCsilicon-layout including four GPU-driven pipeline cores according to theprinciples of the present invention;

FIG. 4E is a schematic representation of an exemplary packaging of theMP-SOC chip of the present invention;

FIG. 4F is a schematic block diagram of the entire MP-SOC architecture,according to the illustrative embodiment of the present invention,wherein the core circuitry of the MP-SOC is outlined and itssubcomponents (i.e. routing center, compositing unit, control unit andprofiling functions) are labeled;

FIG. 5A1 is a block diagram of a first illustrative embodiment of theGraphics and Memory Controller Hub (GMCH) chip technology of the presentinvention (also known as a Memory Bridge or NorthBridge chip) that canbe used to graphics subsystem as comprising dual-IGD (IntegratedGraphics Devices) driven by the MP core circuitry of the presentinvention specified in FIG. 4F, and wherein the external graphics cardis not MP-SOC driven;

FIG. 5A2 is a block diagram of a second illustrative embodiment of theGraphics and Memory Controller Hub (GMCH) chip technology of the presentinvention, wherein the MP-CL circuitry specified in FIG. 4F isintegrated with the dual 3D pipelines (IGDS) of its graphics subsystem,for driving external GPU-based graphics card;

FIG. 5A3 is a block diagram of a third illustrative embodiment of theGMCH chip technology of the present invention, wherein the MP-CLcircuitry specified in FIG. 4F is integrated with the single IGD of itsgraphics subsystem, for driving external GPU-based graphics cards.

FIG. 5A4 is a block diagram of an illustrative embodiment of the MemoryController Hub (MCH) chip technology of the present invention, whereinthe MP-CL circuitry specified in FIG. 4F is integrated, for drivingexternal GPU-based graphics cards, a single multiple-GPU graphics card,or a single-GPU graphics card;

FIG. 5B1 is a schematic representation of a high-performance graphicssystem of the present invention employing the GMCH chip technology ofthe present invention shown in FIG. 5A1 or 5A2, wherein the MP-CLcircuitry specified in FIG. 4F is integrated is integrated with its dualIDG processors, for driving a single display device;

FIG. 5B2 is a schematic representation of a graphics system of thepresent invention employing either the GMCH chip technology shown inFIG. 5A3 or the MCH chip technology shown in FIG. 5A4, wherein the MP-CLcircuitry specified in FIG. 4F is integrated, for driving multiplesingle-GPU based graphics cards interfaced to multiple display devices;

FIG. 5B3 is a schematic representation of a graphics system of thepresent invention employing either the GMCH chip technology shown inFIG. 5A3 or the MCH chip technology shown in FIG. 5A4, wherein the MP-CLcircuitry specified in FIG. 4F is integrated therein, for driving amulti-GPU based graphics card interfaced to a display device;

FIG. 5B4 is a schematic representation of a graphics system of thepresent invention employing either the GMCH chip technology shown inFIG. 5A3 or the MCH chip technology shown in FIG. 5A4, wherein MP-SOCCore Logic circuitry integrated therein is used to drive a single-GPUbased graphics card interfaced to a display device;

FIG. 6 is the software block diagram for a computing system employingMP-SOC or MP-CL based technology according to the illustrativeembodiment of the present invention;

FIG. 7A is a schematic block diagram further illustrating the modulesthat comprise the multi-pipe software drivers of the computing systemillustrated in FIG. 6;

FIG. 7B is a flow chart illustrating the steps carried out by themechanism that runs the three parallelization modes (i.e. ObjectDivision, Image Division and Time Division) within the MP-SOC-based aswell as MP-CL based devices and systems of the present invention;

FIG. 8 is a schematic representation illustrating the object-divisionconfiguration of the MP-SOC and/or MP-CL based system of the presentinvention;

FIG. 9 is a schematic representation illustrating the image-divisionconfiguration of the MP-SOC and/or MP-CL based system of the presentinvention;

FIG. 10 is a schematic representation illustrating the time-divisionconfiguration of the MP-SOC and/or MP-CL based system of the presentinvention;

FIG. 11 is a flowchart illustrating the process for distributingpolygons between multiple GPU-driven pipeline cores along theMP-SOC-based and/or MP-CL based system of the present invention; and

FIG. 12 shows an example of eight (8) GPU-driven pipeline cores arrangedas a combination of parallel modes, in accordance with the principles ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The techniques taught in Applicant's prior PCT application No.PCT/IL04/001069, published as WIPO Publication No. WO 2005/050557 A2,incorporated herein by reference, teach the use of a graphics scalableHub architecture, comprised of Hardware Hub and Software Hub Driver,which serves to glue together (i.e. functioning in parallel)off-the-shelf GPU chips for the purpose of providing a high performanceand scalable visualization solution, object division decompositionalgorithm, employing multiple parallel modes and a combination thereof,and adaptive parallel mode management. Also, PCT Application No.PCT/IL2004/000079, published as WIPO Publication No. WO 2004/070652 A2,incorporated herein by reference, teaches the use of a compositing imagemechanism based on associative decision making, to provide fast andnon-expensive re-compositing of frame buffers as part of Object Divisionparallelism.

The approaches taught in Applicant's PCT Applications identified abovehave numerous advantages and benefits, namely the ability to constructpowerful parallel systems by use of off-the-shelf GPUs, transparently toexisting applications. However, in many applications, it will bedesirable to provide such benefits in conventional graphics systems,using an alternative approach, namely: by providing PCs with a graphicsprocessing and display architecture employing powerful graphicsprocessing and display system realized on monolithic silicon chips, forthe purpose of delivering high performance, high frame-rate stability ofgraphic solutions at relatively low-cost, and transparency to existinggraphics applications.

The benefits of this novel alternative approach include VLSI-basedminiaturization of multi-GPU clusters, high bandwidth of inter-GPUcommunication, lower power and heat dissipation, no redundancy ofcomponents, and low cost. Details on practicing this alternativeapproach will now be described below.

In general, the present invention disclosed herein teaches an improvedway of and a means for parallelizing graphics functions on asemiconductor level, as a multiple graphic pipeline architecturerealized on a single chip, preferably of monolithic construction. Forconvenience of expression, such a device is termed herein as a“multi-pipe system on chip” or “MP-SOC”. This system “on a silicon chip”comprises a cluster of GPU-driven pipeline cores organized in flexibletopology, allowing different parallelization schemes. Theoretically, thenumber of pipeline cores is unlimited, restricted only by silicon areaconsiderations. The MP-SOC is driven by software driver modes, whichreside resident to the host CPU. The variety of parallelization schemesenables performance optimization. These schemes are time, image andobject division, and derivatives thereof.

The illustrative embodiment of the present invention enjoys theadvantages of a multi GPU chip, namely: bypassing the convergelimitation of a single GPU, while at the same time it gets rid of theinherent problems of a multi-GPU system, such as restricted bandwidth ofinter-GPU communication, mechanical complexity (size, power, and heat),redundancy of components, and high cost.

As shown in FIG. 4A, the physical graphic system of the presentembodiment comprises a conventional motherboard (418) and MP-SOC basedgraphic card (415). The motherboard carries the usual set of components,which are CPU (411), system memory (412), Memory Bridge of I/O chipset(413), and other non-graphic components as well (see FIG. 1A for thecomplete set of components residing on a PC motherboard). The printedcircuit graphic card based on the MP-SOC chip (416) connects to themotherboard via a PCI express 16× lanes connector (414). The card hasalso an output to at least one screen (416). The MP-SOC graphic cardreplaces the conventional single-GPU graphic card on the motherboard.The way the MP-SOC graphic card integrates in a conventional PC systembecomes apparent from comparing FIG. 4A with FIG. 1A By simply replacingthe single-GPU graphic card (circled in FIG. 1A) with the MP-SOC basedcard of the present invention, and replacing its drivers with multi-pipesoft drivers on the host CPU, the system of invention is realized withall of the advantages and benefits described herein. This modificationis completely transparent to the user and application, apart from animproved performance.

FIG. 4B shows a possible physical implementation of the presentinvention. A standard form PC card (421) on which the MP-SOC (422) ismounted, connects to the motherboard (426) of the host computing system,via PCI express 16× lanes connector (423). The display screen isconnected via standard DVI connector (424). Since the multiple pipelineson MP-SOC are anticipated to consume high power, for which the standardsupply via PCI express connector is not adequate, an auxiliary power issupplied to the card via dedicated power cable (425). FIG. 4C shows thePCI express connector (431) on a motherboard to which a MP-SOC basedcard connects. It should be emphasized that the standard physicalimplementation of MP-SOC on a PC card makes it an easy and naturalreplacement of the prior art GPU-driven video graphics cards.

FIGS. 4D and 4E describe an artist's concept of the MP-SOC chip tofurther illustrate a physical implementation of the semiconductordevice. FIG. 4D shows a possible MP-SOC silicon layout. In this examplethere are 4 off-the-shelf cores of graphic pipelines. The number ofcores can be scaled to any number, pending silicon area restrictions.The detailed discussion on the MP-SOC functional units is given below.FIG. 4E shows possible packaging and appearance of the MP-SOC chip. Asmentioned before, this chip, along with other peripheral components(e.g. memory chips, bus chips, etc.) intends to be mounted on a standardsized PCB (printed circuit board) and used as a sole graphic card in aPC system, replacing prior art video graphics cards. Production ofMP-SOC based cards can be carried out by graphic card manufacturers(e.g. AsusTech, Gigabyte).

As presented in FIG. 4F, the multi-pipe-SOC architecture comprises thefollowing components:

-   -   Routing center which is located on the CPU bus (e.g. PCI express        of 16 lanes). It distributes the graphics data stream, coming        from CPU among graphic pipeline cores, and then collects the        rendered results (frame buffers) from cores, to the compositing        unit. The way data is distributed is dictated by the control        unit, depending on current parallelization mode.    -   Compositing unit re-composes the partial frame buffers according        to the ongoing parallelization mode.    -   Control unit is under control of the CPU-resident soft        multi-pipe driver. It is responsible for configuration and        functioning of the entire MP-SOC system according to the        parallelization mode.    -   Processing element (PE) unit with internal or external memory,        and optional cache memory. The PE can be any kind of        processor-on-chip according to architectural needs. Besides        serving the PE, the cache and memory can be used to cache        graphics data common to all pipeline cores, such as textures,        vertex objects, etc.    -   Multiple GPU-driven pipeline cores. These cores may, but need        not to be of proprietary designed. They can be originally        designed as a regular single core GPU.    -   Profiling functions unit. This unit delivers to the multi-pipe        driver a benchmarking data such as memory speed, memory usage in        bytes, total pixels rendered, geometric data entering rendering,        frame rate, workload of each pipeline core, load balance among        pipeline cores, volumes of transferred data, textures count, and        depth complexity.    -   Display interface, capable of running single or multiple        screens.

As specified in FIG. 4F, the Multi-Pipeline Core Logic (MP-CL) circuitryof the present invention (460) comprises: the Routing Center 461,Compositing Unit 462, Control Unit 463, and Profiling Unit 464. Thiscore plays central role in other embodiments of present invention,namely: integration of the MP-CL circuitry (460) of the presentinvention within the memory bridge component of the CPU chipsets. Asdescribed in FIGS. 5A1 through 5B4, there are various ways ofintegrating such technology into such CPU chipsets, but regardless ofhow the integration occurs, the goal will be typically the same, namely:to amplify all 3D graphic activities inside the chipset.

FIG. 5A1 shows a first illustrative embodiment of the Graphics andMemory Controller Hub (GMCH) chip of present invention in which allgraphic components are duplicated and driven for parallelism by theMP-CL circuitry 460 of the present invention. As shown, the graphicssubsystem comprises dual-IGD (Integrated Graphics Devices) in which theMP-CL circuitry (460) specified in FIG. 4F is integrated as shown. Thecommand stream is delivered from processor to graphic engines viaRouting Center 461. The data flows from system memory to Routing Center,as shown. The partial results are being composited according toparallelization method and sent to display.

Since the 2D and Video activities are much less demanding in comparisonto 3D, these two components are not necessarily duplicated, as shown inFIG. 5A2. In FIG. 5A2, a second illustrative embodiment of the Graphicsand Memory Controller Hub (GMCH) chip of the present invention is showncomprising a graphics subsystem including a dual-3D-pipeline driven bythe MP-CL circuitry of the present invention, and wherein the video and2D engines are not duplicated. Rather, only the 3D pipeline isduplicated and parallelized. In either case, the external graphic card,which is not MP-CL circuitry driven, can be connected, switching out theIGD. A Scalable Graphics Hub (SGH) running multiple GPUs can replace thestandard graphics card. SGH is another related invention described inApplicant's PCT/IL04/001069 which is incorporated herein by reference inits entirety.

The GMCH or MCH chip technology of the present invention can be used toparallelize multiple GPUs which are external thereto. This option isdepicted in FIGS. 5A3 and 5A4.

FIG. 5A3 shows a third illustrative embodiment of the GMCH chiptechnology of the present invention as comprising a graphics subsystemhaving a single IGD with MP-CL circuitry (460) integrated therein asshown, for driving external GPU-based graphics cards. In thisembodiment, the external GPUs are driven by MP-CL circuitry of thepresent invention, and such GPUs can be organized either as multiplegraphics cards, or as multiple GPUs on single graphics card.

FIG. 5A4 shows an illustrative embodiment of the Memory Controller Hub(MCH) chip technology of the present invention as comprising MP-CLcircuitry (460) integrated therein as shown for driving externalGPU-based graphics cards, a single multiple-GPU graphics card, or asingle-GPU graphics card. In this illustrative embodiment, only therouting center (461) is used for passing data to and from the externalGPUs on a single or multiple graphics cards.

Notably, the GMCH or MCH chip technology of the present invention can beused as a general way of and means for driving all graphic cards,regardless of the vendor. Since the MP-CL circuitry of the presentinvention is generic in its very nature (i.e. the technology is capableof running/driving any off-the-shelf GPU), such innovative circuitrymakes the GMCH or MCH chips of the present invention generic in terms ofapplication, as well.

FIGS. 5B1 through 5B4 show different graphic systems utilizing thealternative ways of integrating the GMCH and MCH chip technology of thepresent invention.

FIG. 5B1 shows a high-performance graphics system of the presentinvention employing the GMCH chip technology of the present invention(523) shown in FIG. 5A1 or 5A2, wherein the MP-CL circuitry specified inFIG. 4F is integrated with its dual IDG processors, for driving a singledisplay device.

FIG. 5B2 shows a high-performance graphics system of the presentinvention employing either the GMCH chip technology (523′) shown in FIG.5A3 or the MCH chip technology (523″) shown in FIG. 5A4, wherein theMP-CL circuitry specified in FIG. 4F is integrated, for driving multiplesingle-GPU based graphics cards interfaced to multiple display devices.

FIG. 5B3 shows another a high-performance graphics system of the presentinvention employing either the GMCH chip (523′) technology shown in FIG.5A3 or the MCH chip technology (523″) shown in FIG. 5A4, wherein theMP-CL circuitry specified in FIG. 4F is integrated therein, for drivinga multi-GPU based graphics card interfaced to a display device.

Finally, FIG. 5B4 shows yet another high-performance graphics system ofthe present invention employing either the GMCH chip technology (523′)shown in FIG. 5A3 or the MCH chip technology (523″) shown in FIG. 5A4,wherein MP-CL circuitry integrated therein is used to drive a single-GPUbased graphics card interfaced to a display device.

Integration of MP-CL circuitry (460) into graphics chip designsaccording to the principles of the present invention results in a powergraphics chip technology that is capable of driving virtually anygraphic card, regardless of its vendor, with levels of photo-realisticperformance that have been hitherto unattainable.

Having described the MP-SOC and MP-CL technology of the presentinvention, it is appropriate at this juncture to now describe (i)software components that would be typically used in conjunctiontherewith, and (ii) the operation of an overall computing systememploying such technology, and its various modes of parallelization. Inconnection therewith, it is noted that FIGS. 6 though 12 apply equallyto computing systems employing either MP-SOC or MP-CL technology, orcombinations thereof, in accordance with the principles of the presentinvention.

As shown in FIG. 6, the software of the system comprises the graphicapplication, graphics library (e.g. graphic standards OpenGL orDirectX), and proprietary soft driver (multi-pipe driver). The genericgraphics application needs no modifications or special porting effortsto run on the MP-SOC of the present invention, as well as on computingsystems employing MP-CL circuitry described in great detail above.

FIG. 7 shows a functional block diagram presenting the main tasks of themulti-pipe driver, according to an illustrative embodiment of thepresent invention. The multi-pipe driver carries on at least thefollowing actions/functions:

-   -   Generic GPU drivers. Perform all the functions of a generic GPU        driver associated with interaction with the Operation System,        graphic library (e.g. OpenGL or DirectX), and controlling the        GPUs.    -   Distributed graphic functions control. This module performs all        functions associated with carrying on the different        parallelization modes according to parallelization policy        management. In each mode, the data is differently distributed        and re-composed among pipelines, as will be described in greater        detail hereinafter.    -   State monitoring. The graphic libraries (e.g. OpenGL and        DirectX) are state machines. Parallelization must preserve        cohesive state across the graphic system. It is done by        continuous analysis of all incoming commands, while the state        commands and some of the data must be multiplicated to all        pipelines in order to preserve the valid state across the        graphic pipelines. A specific problem is posed by the class        called Blocking operations such as Flush, Swap, Alpha blending,        which affect the entire graphic system, setting the system to        blocking mode. Blocking operations are exceptional in that they        require a composed valid FB data, thus in the parallel setting        of the present invention, they have an effect on all pipeline        cores. A more detailed description of handling Blocking        operations will be given hereinafter.    -   Application profiling and analysis module. This module performs        real-time profiling and analysis of the running application. It        continuously monitors of application parameters in the system,        such as memory speed, memory usage in bytes, total pixels        rendered, geometric data entering rendering, frame rate,        workload of each pipeline core, load balance among graphic        pipelines, volumes of transferred data, textures count, and        depth complexity, etc. The profiler module identifies problem        areas within the graphics system which cause bottlenecks. The        profiler module requires inputs from the registers of the        multi-pipe cores, registers of the MP-SOC control unit or MC-CL        circuitry, and graphic API commands (e.g. OpenGL, DirectX).    -   Parallelism policy management makes a decision on the parallel        mode to be performed, on a per-frame basis, based on the above        profiling and analysis. The decision is then carried out by        means of the control unit in the MP-SOC or MC-CL circuitry of        the present invention.

A major feature of the present invention is its topological flexibilitywhich enables revamping of performance bottlenecks. Such flexibility isgained by rearranging the cluster of graphics pipelines by means ofrouting center and different merging schemes at the compositing unit.Different parallelization schemes affect different performancebottlenecks. Therefore bottlenecks, identified by the profiling module,can be cured by utilizing the corresponding parallelization scheme.

The flowchart of FIG. 7B describes the mechanism that runs the threeparallel modes: the Object Division mode, the Image Division mode andthe Time Division mode. The mechanism combines the activity of softdriver modules with MP-SOC and MP-CL units. The cycle of the flowchartis one frame. The mode to begin with is the Object Division (OD), sinceit is the preferred parallel mode, as will be explained hereinafter. Theprofiling and analysis of the application is constantly on, undercontrol of the soft Profile and Analysis module (S-PA). Every frame theParallel Policy Management (S-PPM) module checks for the optimal mode,to choose from the three parallelization modes.

Let us assume that the Object Division (OD) path was taken. TheDistributed Graphic Functions Control (S-DGFC) module configures theentire system for OD, characterized by distribution of geometric dataand the compositing algorithm in use. This configuration is shown inFIG. 8, and described in detail later on. The S-DGFC module decomposesthe geometric data into partitions, each sent by the Routing unit (C-RC)to different GPU-driven pipe core (C-PC) for rendering. The renderedstream of data is monitored by the State Monitoring (S-SM) module forblocking commands, as shown in FIG. 11, and described in great detailhereinafter. When the rendering is completed, all the Frame Buffers aremoved by the Control Unit (C-Ctrl) to Compositing Unit (C-CU) tocomposite all buffers to a single one, based on depth test (as explainedin detail below). The final FB is moved to Display by Display InterfaceUnit (C-DI). At the end of the frame the S-PA and S-PPM modules test forthe option of changing the parallel mode. If a decision was taken tostay with the same mode, a new OD frame starts with another datapartition. Otherwise, a new test for an optimal mode is performed byS-PA and S-PPM modules.

The left path in the flowchart is Image Division (ID) operation. The IDconfiguration, as set by the S-DGFC, is also shown in FIG. 9, anddescribed later in greater detail. It is characterized by broadcastingof the same data among all pipe cores, and by image based compositingalgorithm. The partitioning of image among pipe cores is done by S-DGFC.The data is broadcast by the Routing Center, and then rendered at pipecores (C-PC), while each one is designated another portion of image.Upon accomplishing of rendering, the C-Ctrl moves the partial FBs to thecompositing unit (C-CU) for reconstruction of the complete image. Thenthe C-DI moves the FB to Display. Finally the Change test is performedby S-PS and S-PPM modules. Pending the result, a new frame will continuethe ID mode, or switch to another mode.

The Time Division mode alternates frames among the GPU-driven pipecores. It is set for alternation by the S-GDFC module, while each coreis designated a frame data by S-DGFC and delivered by the C-RC unit.Each core (C-PC) generates a frame, in a line. Then the C-Ctrl moves thematured FB via compositing unit to the Display Interface, and out to thedisplay. Actually, the compositing unit in this mode acts just as atransit. Finally there is a change-mode test by S-PA and S-PPM modules,the same as in the other modes before.

FIG. 8 describes the object-division parallelization scheme. The softdriver, and specifically, the Distributed Graphic Functions Controlmodule, breaks down the polygon data of a scene into N partial streams(N—the number of participating pipeline cores). The entire data is sentby the GPU Drivers module to the MP-SOC Routing Center, whichdistributes the data to N pipeline cores for rendering, according to thesoft driver's partition, each of approximately 1/N polygons. Renderingin the pipeline cores is done under the monitoring of the StateMonitoring module of the soft driver (FIG. 11 and detailed descriptionbelow). The resultant full frame buffers are gathered in the CompositingUnit. They are depth-composed, pixel by pixel, to find the final set ofvisible pixels. At each x-y coordinate all hidden pixels are eliminatedby compositing mechanism. The final frame buffer is moved out todisplay.

FIG. 9 describes the image-division parallelization scheme, which ischosen by the Parallelism Policy Management module, as a result ofprofiling, analysis, and decision making in the Profiling and Analysismodule of the soft driver. Each pipeline core is designated a unique 1/Npart of the screen. The complete polygon data is delivered to each ofthe pipeline cores via the GPU Driver module and Routing Center. Theparallel rendering in pipeline cores results in a partial frame bufferat each. The image segments are moved to the Compositing Unit for 2Dmerging into a single image and moved out to the display.

FIG. 10 describes the time-division parallelization scheme which ischosen by Parallelism Policy Management module, as a result ofprofiling, analysis, and decision making in the Profiling and Analysismodule of the soft driver. The Distributed Graphic Functions Controlmodule, through GPU Drivers module, divides the frames into N cycles(N=number of cores) letting each core time slot of N frames forrendering the entire polygon data. Therefore the scene polygon data isdistributed, via Router, to a different pipeline core at a time Eachcore performs rendering during N cycles, and outputs its full framebuffer to display, for a single frame. The Compositing unit functionshere as a simple switch, alternating the access to the Display among allthe pipeline cores.

Different parallelization schemes resolve different performancebottlenecks. Therefore bottlenecks must be identified and theneliminated (or reduced) by applying the right scheme at the right time.

As shown in FIG. 7B, the profiler identifies problem areas within thegraphics system which cause bottlenecks. It is implemented in theApplication Profiling and Analysis module of the driver. The profilermodule requires such inputs as usage of graphic API commands (e.g.OpenGL, DirectX, other), memory speed, memory usage in bytes, totalpixels rendered, geometric data entering rendering, frame rate, workloadof each GPU, load balance among GPUs, volumes of transferred data,textures count, and depth complexity, etc. These data types arecollected from the following sources within the MP-SOC as well as MP-CLbased graphics systems:

-   -   1. The profiling functions unit in MP-SOC as well as MP-CL        circuitry    -   2. The driver    -   3. The pipeline cores    -   4. Chipset Architecture Performance (CHAP) Counters        Typically, the performance data is retrieved on a frame time        basis, however, the periodicity can also be a configuration        attribute of the profiler, or can be set based on a detected        configuration event which the profiler is designed to detect        before retrieving performance data.

The analysis, resulting in the selection of a preferred parallel methodis based on the assumption that in a well defined case (describedbelow), object-division method supersedes the other division modes inthat it reduces more bottlenecks. In contrast to image-division, thatreduces only the fragment/fill bound processing at each pipeline core,the object-division relaxes virtually all bottleneck across thepipeline: (i) the geometry (i.e. polygons, lines, dots, etc) transformprocessing is offloaded at each pipeline, handling only 1/N of polygons(N—number of participating pipeline cores); (ii) fill bound processingis reduced since less polygons are feeding the rasterizer, (iii) lessgeometry memory is needed; (iv) less texture memory is needed.

Although the time-division method releases bottlenecks by allowing toeach pipeline core more time per frame generation, this method suffersfrom severe problems such as CPU bottlenecks, wherein the pipeline coresgenerated frame buffers that are not available to each other, and aswell as frequent cases of pipeline latency. Therefore this method is notsuitable to all applications. Consequently, due to its superiority asbottleneck opener, object-division becomes the primary parallel mode.

The following object division algorithm distributes polygons among themultiple graphic pipeline cores. Typical application generates a streamof graphic calls that includes blocks of graphic data; each blockconsists of a list of geometric operations, such as single vertexoperations or buffer based operations (vertex array). Typically, thedecomposition algorithm splits the data between pipeline corespreserving the blocks as basic data units. Geometric operations areattached to the block(s) of data, instructing the way the data ishandled. A block is directed to designated GPU. However, there areoperations belonging to the group of Blocking Operations, such as Flush,Swap, Alpha blending, which affect the entire graphic system, settingthe system to blocking mode. Blocking operations are exceptional in thatthey require a composed valid FB data, thus in the parallel setting ofthe present invention, they have an effect on all pipeline cores.Therefore, whenever one of the Blocking operations is issued, all thepipeline cores must be synchronized. Each frame has at least 2 blockingoperations: Flush and Swap, which terminate the frame.

FIG. 11 presents a flowchart describing an algorithm for distributingpolygons among multiple GPU-driven pipeline cores, according to anillustrative embodiment of the present invention. The frame activitystarts with distributing blocks of data among GPUs. Each graphicoperation is tested for blocking mode at step 1112. In a regular path(non-blocking path), data is redirected to the designated pipeline coreat step 1113. This loop is repeated until a blocking operation isdetected.

When the blocking operation is detected, all pipeline cores must besynchronized at step 1114 by at least the following sequence:

-   -   performing a flush operation in order to terminate rendering and        clean up the internal pipeline (flushing) in pipeline core;    -   performing a composition in order to merge the contents of all        FBs into a single FB; and    -   transmitting the contents of said single FB back to all pipeline        cores, in order to create a common ground for continuation.

The Swap operation activates the double buffering mechanism, swappingthe back and front color buffers. If Swap is detected at step 1115, itmeans that the composited frame must be terminated at all pipelinecores, except pipeline 0. All pipeline cores have the final composedcontents of a FB designated to store said contents, but only the oneconnected to the screen (pipelines) displays the image at step 1116.

Another case is operations that are applied globally to the scene andneed to be broadcasted to all the pipeline cores. If one of the otherblocking operations is identified, such as Alpha blending fortransparency, then all pipeline cores are flushed as before at step1114, and merged into a common FB. This time the Swap operation is notdetected (step 1115), therefore all pipeline cores have the same data,and as long as the blocking mode is on (step 1117), all of them keepprocessing the same data (step 1118). If the end of the block mode isdetected at step 1117, pipeline cores return working on designated data(step 1113).

The relative advantage of object-division depends very much on depthcomplexity of the scene. Depth complexity is the number of fragmentreplacements as a result of depth tests (the number of polygons drawn onevery pixel). In the ideal case of no fragment replacement (e.g. allpolygons of the scene are located on the same depth level), the fill isreduced according to the reduced number of polygons (as for 2 pipelinecores). However, when depth complexity is getting high, the advantage ofobject-division drops down, and in some cases the image-division mayeven perform better, e.g. applications with small number of polygons andhigh volume of textures.

In addition, the present invention introduces a dynamic load-balancingtechnique that combines the object division method with the imagedivision and time division methods in image and time domains, based onthe load exhibits by previous processing stages. Combining all the threeparallel methods into a unified framework dramatically increases theframe rate stability of the graphic system.

FIG. 12 discloses a sample configuration of the system, employing 8pipeline cores, according to an embodiment of the present invention.According to the above sample configuration, a balanced graphicapplication is assumed. The pipeline cores are divided into two groupsfor time division parallelism. Pipeline cores indexed with 1, 2, 3, and4 are configured to process even frames and pipeline cores indexed with5, 6, 7, and 8 are configured to process odd frames. Within each group,two pipeline core subgroups are set for image division: the pipelinecores with the lower indexes (1,2 and 5,6 respectively) are configuredto process half of the screen, and the high-indexed pipeline cores (3,4and 7,8 respectively) are configured to process the other half. Finally,for the object division, pipeline cores indexed with 1, 3, 5 and 7 arefed with half of the objects, and pipeline cores indexed with 2, 4, 6and 8 are fed with the other half of the objects.

If at some point the system detects that the bottlenecks exhibited inprevious frames occur at the raster stage of the pipeline, it means thatfragment processing dominates the time it takes to render the frames andthat the configuration is imbalanced. At that point the pipeline coresare reconfigured, so that each pipeline core will render a quarter ofthe screen within the respective frame. The original partition for timedivision, between pipeline cores 1,2,3,4 and between 5,6,7,8 stillholds, but pipeline core 2 and pipeline core 5 are configured to renderthe first quarter of screen in even and odd frames respectively.Pipeline cores 1 and 6—render the second quarter, pipeline cores 4 and7—the third quarter, and pipeline cores 3 and 8—the forth quarter. Noobject division is implied.

In addition, if at some point the system detects that the bottleneckexhibited in previous frames occurs at the geometry stage of the pipe,the pipeline cores are reconfigured, so that each pipeline core willprocess a quarter of the geometrical data within the respective frame.That is, pipeline cores 3 and 5 are configured to process the firstquarter of the polygons in even and odd frames respectively. Pipelinecores 1 and 7—render the second quarter, pipeline cores 4 and 6—thethird quarter and pipeline cores 2 and 8—the forth quarter. No imagedivision is implied.

It should be noted, that taking 8 pipeline cores is sufficient in orderto combine all three parallel modes, which are time, image and objectdivision modes, per frame. Taking the number of pipeline cores largerthan 8, also enables combining all 3 modes, but in a non-symmetricfashion. The flexibility also exists in frame count in a time divisioncycle. In the above example, the cluster of 8 pipeline cores was brokendown into the two groups, each group handling a frame. However, it ispossible to extend the number of frames in a time division mode to asequence, which is longer than 2 frames, for example 3 or 4 frames.

Taking a smaller number of pipeline cores still allows the combinationof the parallel modes, however can have the combination of two modesonly. For example, taking only 4 pipeline cores enables to combine imageand object division modes, without time division mode. It is clearlyunderstood from FIG. 12, while taking the group of pipeline cores 1-4,which is the left cluster. Similarly, the group of pipeline cores 1,2,5,and 6 which comprise the upper cluster, employs both object and timedivision modes. Finally, the configuration of the group of pipelinecores 2,4,5, and 6, which is the middle cluster, employs image and timedivision modes.

It should be noted, that similarly to the above embodiments, anycombination between the parallel modes can be scheduled to evenlybalance the graphic load.

It also should be noted, that according to the present invention, theparallelization process between all pipeline cores may be based on anobject division mode or image division mode or time division mode or anycombination thereof in order to optimize the processing performance ofeach frame.

The decision on parallel mode is done on a per-frame basis, based on theabove profiling and analysis. It is then carried out by reconfigurationof the parallelization scheme, as described above and shown in FIGS. 8,9, 10 and 12.

The MP-SOC and MP-CL technology architecture of the present inventiondescribed in great detail hereinabove can be readily adapted for use indiverse kinds of graphics processing and display systems. While theillustrative embodiments of the present invention have been described inconnection with PC-type computing systems, it is understood that thepresent invention can be used improve graphical performance in diversekinds of systems including mobile computing devices, embedded systems,as well as scientific and industrial computing systems supportinggraphic visualization of photo-realistic quality.

It is understood that the graphics processing and display technologydescribed in the illustrative embodiments of the present invention maybe modified in a variety of ways which will become readily apparent tothose skilled in the art and having the benefit of the novel teachingsdisclosed herein. All such modifications and variations of theillustrative embodiments thereof shall be deemed to be within the scopeand spirit of the present invention as defined by the Claims toInvention appended hereto.

1. A PC-based computing system having an integrated graphics subsystemsupporting parallel graphics processing operations across a plurality ofdifferent graphics processing units (GPUs) from same or differentvendors, in a manner transparent to graphics applications, said PC-basedcomputing system comprising: system memory for storing software graphicsapplications, software drivers and graphics libraries; an operatingsystem (OS), stored in said system memory; one or more graphicsapplications, stored in said system memory, for generating a stream ofgraphics commands and geometrical data supporting the representation ofone or more 3D objects in a scene having 3D geometrical characteristicsand the viewing of images of said one or more 3D objects in said sceneduring an interactive process carried out between said PC-basedcomputing system and a user thereof; one or more graphics libraries,stored in said system memory, for storing data used to implement saidstream of graphics commands and geometrical data; a central processingunit (CPU) on a motherboard for executing said OS, said graphicsapplications, and said graphics libraries; a CPU bus; a display surfacefor displaying said images by graphically displaying frames of pixeldata; a graphics subsystem integrated within said PC-based computingsystem and supporting parallel graphics processing operations across aplurality of different graphics processing units (GPUs) supplied fromthe same or different vendor, and in a manner transparent to said one ormore graphics applications, and wherein said graphics subsystem includesa graphics controller hub (GCH) chip located on said CPU bus, and havingMulti-Pipeline Core Logic (MP-CL) circuitry including a routing unit anda control unit; wherein said plurality of different GPUs are interfacedwith said GCH chip, wherein each said different GPU supports aGPU-driven pipeline core having a frame buffer (FB) for storing afragment of pixel data, and wherein said GPU-driven pipeline cores arearranged in a parallel architecture and operated according to aparallelization mode of operation, so that said GPU-driven pipelinecores process data in a parallel manner, and wherein at least one ofsaid GPU-driven pipeline cores includes a display interface interfacingwith said display surface; a plurality of vendor-supplied software GPUdrivers, stored in said system memory, for said plurality of differentGPUs; wherein each said vendor-supplied GPU driver (i) allows theGPU-driven pipeline core and said GPU to interact with said OS and saidgraphic libraries, and (ii) controls said GPU during the running of saidgraphics application; and a plurality of software multi-pipe drivers,stored in said system memory, and including (i) a first software modulefor profiling and analyzing said graphics application, includinganalyzing incoming commands, and collecting and analyzing parametersincluding performance data selected from the group consisting of memoryspeed, memory usage in bytes, total pixels rendered, geometric dataentering rendering, frame rate, workload of each GPU-driven pipelinecore, load balance among said GPU-driven pipeline cores, volumes oftransferred data, textures count, and depth complexity, and (ii) asecond software module for controlling said parallelization mode ofoperation; wherein said control unit accepts commands from said softwaremulti-pipe drivers, over said CPU bus, and controls components withinsaid GCH chip, including said routing unit; wherein said routing unitfeeds back performance data to said software multi-pipe drivers, forbalancing the data load among said GPU-driven pipeline cores during saidparallelization mode of operation; wherein, for each image of said 3Dobject to be generated and displayed on said display surface, thefollowing operations are performed: (i) said routing unit routes saidstream of graphic commands and geometrical data, or a portion thereof,from said CPU to one or more of said GPU-driven pipeline cores, (ii) oneor more of said GPU-driven pipeline cores process said stream of graphiccommands and geometrical data, or a portion thereof, during thegeneration of each said frame, while operating in said parallelizationmode, so as to generate pixel data corresponding to at least a portionof said image, and (iii) said routing unit routes pixel data output fromone or more of said GPU-driven pipeline cores during the composition ofeach frame of pixel data, corresponding to a final image, for display onsaid display surface.
 2. The PC-based computing system of claim 1,wherein said GCH chip further comprises a memory unit for storingintermediate processing results from one or more of said GPU-drivenpipeline cores, and data required for composition and transferringframes of pixel data for display.
 3. The PC-based computing system ofclaim 1, wherein said geometrical data comprises a set of scenepolygons, textures and vertex objects.
 4. The PC-based computing systemof claim 1, wherein said graphics commands includes commands selectedfrom the group consisting of display lists and display vertex arrays. 5.The PC-based computing system of claim 1, wherein said graphic librariesare selected from the group consisting of OpenGL and DirectX.
 6. ThePC-based computing system of claim 1, wherein when said parallelizationmode of operation is a time division mode, the GPU in each saidGPU-driven pipeline core renders a different frame of pixel data fordisplay on said display surface at a different moment of time.
 7. ThePC-based computing system of claim 1, wherein when said parallelizationmode of operation is an image division mode, each GPU on each saidexternal GPU-driven pipeline core renders a subset of the pixels used tocompose each frame of pixel data to be displayed on said displaysurface.
 8. The PC-based computing system of claim 1, wherein when saidparallelization mode of operation is an object division mode, the 3Dobject which is to be displayed as an image consisting of a frame ofpixels, is decomposed into said stream of graphic commands andgeometrical data which are distributed to said GPU-driven pipeline corefor rendering the frames of pixel data compositing the images to bedisplayed on said display surface.
 9. The PC-based computing system ofclaim 8, wherein each said 3D object is decomposable into a plurality ofpolygons, and wherein said geometrical data comprises the vertices ofsaid polygons.
 10. The PC-based computing system of claim 1, whereinsaid software multi-pipe drivers further comprise a third softwaremodule installed in said system memory for continuously analyzingsubstantially all incoming commands, including state commands,transferring certain state commands and some of the data all of saidGPU-driven pipeline cores so as to preserve the valid state across saidGPU-driven pipeline cores.
 11. The PC-based computing system of claim10, wherein said third software modules uses inputs from (i) theregisters of said GPU-driven pipeline cores, and (ii) registers of saidcontrol unit, and graphic API commands.
 12. The PC-based computingsystem of claim 1, wherein said second software module controls saidparallelization mode of operation during the generation of each saidframe of pixel data during the running of said graphics application. 13.The PC-based computing system of claim 1, wherein said GPU-drivenpipeline cores are arranged in a parallel architecture and operatedaccording to one or more parallelization modes of operation, determinedduring the generation of each said frame of pixel data, so that saidGPU-driven pipeline cores process data in a parallel manner.
 14. ThePC-based computing system of claim 13, wherein said second softwaremodule dynamically determins and controls said parallelization mode ofoperation during any particular frame of pixel data generation anddisplay.
 15. The PC-based computing system of claim 14, wherein saidsecond software module dynamically determines and controls saidparallelization mode of operation during any particular frame of pixeldata generation and display, based on factors including the timerequired to render previous frames of pixel data and bottlenecksexhibited in vertex processing and pixel processing during the renderingof said previous frames of pixel data.
 16. The PC-based computing systemof claim 13, wherein said parallelization mode of operation is selectedfrom the group consisting of an object division mode, an image divisionmode and a time division mode, and wherein said second software moduledynamically determines and controls said parallelization mode during anyparticular frame of pixel data generation and display, based on anycombination of said object division mode, said image division mode andsaid time division mode.
 17. The PC-based computing system of claim 1,wherein said GCH chip is a memory bridge chip, which interfaces withsaid system memory.
 18. The PC-based computing system of claim 1,wherein said GCH chip is realized as a system-on-a-chip (SOC)architecture.
 19. The PC-based computing system of claim 1, wherein saiddifferent GPUs are located (i) within an integrated graphics device(IGD) within said GCH chip, and also (ii) on one or more externalGPU-based graphics cards from the same or different vendors.
 20. ThePC-based computing system of claim 1, wherein said different GPUs arelocated on a plurality of external GPU-based graphics cards fromdifferent vendors.
 21. The PC-based computing system of claim 1, whereinsaid CGH chip further comprises a compositing unit for compositing eachframe of pixel data, corresponding to said final image, for display onsaid display surface.
 22. The PC-based computing system of claim 21,wherein said routing unit routes pixel data output from one or more ofsaid GPU-driven pipeline cores to said compositing unit, during thecomposition of each frame of pixel data, corresponding to said finalimage, for display on said display surface.